Theoretical Analysis of Continuous Heat Extraction from Absorber of Solar Still for Improving the Productivity

This paper communicates the theoretical analysis of continuous waste heat extraction from the other side of absorber plate. For theoretical analysis two conditions are determined one is the mass of water in the absorber and another one is mass flow rate of water around the absorber plate. Results indicated that the water temperature is reached maximum at 10 kg of mass and 5 kg/hr mass flow of water and the heat extracted from the absorber is higher at optimum mass flow of 5 kg/hr. Also, the higher temperature difference between the water and the collector cover is found during the off-shine period. The maximum achievable hourly productivity of 0.9 and 0.5 kg is found for the solar still with and without circulation respectively. The yield from present model with continuous heat extraction is increased from 3 to 5.5 kg/m2. As the approached method is more new to the society it may be determined by Agouz- Nagarajan- Sathyamurthy (ANS) model

Synthesis, characterisation and thermo-physical investigations on magnesia nanoparticles dispersed in ethylene glycol–DI water (50:50)

In the present work, magnesia nanoparticles (17 nm) were synthesised by solution combustion and characterised using X-ray diffraction and scanning electron microscopy. Nanofluid prepared by magnesia dispersion in ethylene glycol and deionised water (50:50) is characterised using Fourier transform infrared, dynamic light scattering (DLS) and Zeta potential measurement. The -41 mV zeta potential confirms nanofluid stability. The average particle size in the nanofluid obtained by the DLS method is 33 nm, whereas the crystallite size is 17 nm as per the Scherrer relation. The nanofluid properties were determined under varying volume concentration (0.025, 0.05, 0.1, 0.2%) and temperature (25–60°C). The viscosity measured by using a rotational viscometer decreases with increase in the temperature, whereas the thermal conductivity and specific heat, measured by using a KD2 Pro analyser and a differential scanning calorimeter, respectively, increases. With the increase in volume concentration, thermal conductivity, and viscosity increases, whereas specific heat decreases. The maximum thermal conductivity enhancement and specific heat diminution was 15.6 and 20.5%, respectively, for 0.2% concentration and the minimum viscosity was 2.2% for 0.025% concentration at 60°C. Based on the measured data, new correlations have been proposed